1. Field of the Invention
The present invention relates generally to networks, and in particular to managing traffic congestion in end-to-end networks.
2. Background Information
Different types of networks, each optimized for a specific task, are used for tasks such as storage, interprocessor communication (IPC), and local area network (LAN) traffic. Fibre Channel networks are commonly used for storage traffic, InfiniBand™ or Myrinet networks are used for IPC traffic, and Ethernet networks are commonly used for LAN traffic.
Storage traffic typically involves transferring large amounts of data and requires high bandwidth, whereas IPC traffic involves transferring small amounts of data that are delay sensitive. Having a consolidated fabric for all three types of data that meets the performance and latency requirements can lower the overall costs by using switches and network adapters that do not provide congestion management functionality in a network system. In order for Ethernet to become the choice for a consolidated fabric, it will have to become (nearly) lossless. This is due to the fact that, unlike InfiniBand™ or Fibre Channel, dropping packets in an Ethernet switch is acceptable during periods of network congestion.
Currently the IEEE 802.1Qau working group is involved in standardizing a set of congestion control mechanisms for the next generation Ethernet. Most proposals require that all switches and all endpoints in the fabric support the congestion management scheme. This increases the hardware complexity for all network components and requires complicated queuing mechanisms and extensive parameter tuning for it to work properly in the fabric.